This paper presents the instantiation of an abstract pointcut definition language (APL) for aspect oriented middlewares in a concrete language: Re-AspectLua. The choice of Re-AspectLua as concrete language was motivated by its support to aspect reuse and heterogeneous composition between aspects and base elements. Such features are essential in the aspect oriented middleware context. In order to meet the requirements specified by the APL definition, our work includes the following extensions to RE-AspectLua: (i) execution joinpoints; (ii) a set of logical operators to combine pointcut expressions; (iii) support to context properties associated to function calls. Besides presenting the APL instantiation, this paper illustrates the use of the proposed extended version of RE-AspectLua in a case study that defines how distribution protocols are represented as aspects and woven with other basic services provided by an aspect oriented middleware.